CVE-2018-16342 in ShowDoc
Summary
by MITRE
ShowDoc v1.8.0 has XSS via a new page.
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Analysis
by VulDB Data Team • 05/06/2023
CVE-2018-16342 represents a cross-site scripting vulnerability discovered in ShowDoc version 1.8.0, where an attacker can inject malicious scripts through a new page functionality. This vulnerability falls under the CWE-79 category of Cross-Site Scripting, specifically manifesting as a stored XSS flaw that allows persistent script execution within the application's context. The vulnerability arises from insufficient input validation and output sanitization mechanisms within the page creation feature, enabling unauthorized users to submit malicious payloads that execute when other users view the affected content. The flaw exists in the application's handling of user-supplied data during page creation processes, where submitted content fails to undergo proper sanitization before being rendered to end users.
The operational impact of this vulnerability extends beyond simple script injection, as it provides attackers with potential access to sensitive user data, session hijacking capabilities, and the ability to perform actions on behalf of authenticated users. Attackers can exploit this weakness to steal cookies, session tokens, or personal information from victims who access the compromised pages. The vulnerability is particularly concerning in environments where ShowDoc serves as a collaborative documentation platform, as it allows malicious actors to compromise multiple users within the same organization. This type of attack aligns with ATT&CK technique T1566.001 for Initial Access through spearphishing attachments and T1071.001 for Application Layer Protocol: Web Protocols, as the exploitation occurs through web-based interfaces and user interactions with compromised content.
The technical implementation of this vulnerability involves the application's failure to properly escape or filter user input when processing new page content, particularly in areas where HTML or JavaScript code might be interpreted as part of the page rendering process. This creates a persistent threat vector where malicious scripts can execute in the context of other users' browsers, potentially leading to complete system compromise if combined with other exploitation techniques. The vulnerability affects all users who can create or modify pages within the ShowDoc application, making it particularly dangerous in shared or multi-user environments where privilege escalation might occur.
Mitigation strategies should include immediate patching of the ShowDoc application to version 1.8.1 or later, which contains the necessary input validation and sanitization fixes. Organizations should implement comprehensive input filtering mechanisms that sanitize all user-supplied content before storage or rendering, particularly focusing on HTML and JavaScript content. Additional protective measures include implementing Content Security Policy headers to limit script execution, enabling proper output encoding for all dynamic content, and conducting regular security audits of user input handling processes. Network-based solutions such as web application firewalls can provide additional protection layers, while user education regarding suspicious content and regular security updates should be maintained to prevent exploitation attempts. The vulnerability demonstrates the critical importance of validating and sanitizing all user inputs as a fundamental security practice, aligning with security frameworks that emphasize defense in depth and the principle of least privilege in web application security.